Generally, MIP6 is a technique for backing up its movement in an internet protocol version 6 (hereinafter, referred to as IPv6) network. The IPv6 is a next version of the internet protocol version 4 (hereinafter, referred to as IPv4) that has been used for an internet transfer protocol, and its normalization has been nearly completed by the internet engineering task force (IETF).
However, the IPv4 has been used in the internet addressing system since it is not completely changed into the IPv6. The change of the IPv4 into IPv6 network does not occur in a moment, and therefore the internet networks are in a mixed state where the IPv4 and IPv6 networks are used together.
Accordingly, an MIP6 standardization has been under way by an MIP6 working group (MIP6 WG) of the IETF by proposing a protocol dual stack MIP6 (hereinafter, referred to as DSMIP6) in order to operate the MIP6 in an environment in which the IPv4 network and the IPv6 network are used in a mixed state. Due to the characteristics of the DSMIP6, the MIP6 mobile node easily moves to different networks or the same network. In this case, a method for detecting movement of an MIP 6 mobile node is necessarily required for performing a binding update (BU) procedure according to the network movement.
However, it is recommended from a DSMIP6 specification to see a separate literature (DNAv4; Detecting Network Attachment in IPv4, RFC4436) for the movement to an IPv6-IPv4 network, but the RFC4436 literature discloses only the movement to an IPv4 network. Therefore, it is difficult to detect the movement of mobile nodes from the IPv6 network to the IPv4 network using the DSMIP6 specification.